A navigation console to steer magnetic instruments under radiological guidance for neuro-vascular interventions

Abstract

The gold-standard for treating some neurovascular diseases such as ischemic stroke is an effective and minimal invasive endovascular technique. The primary instruments used are catheters and guidewires that are inserted into the vasculature through a small incision at the groin [1]. Some instruments have a curved tip allowing for easier access of different vessels as they bifurcate and are navigated by pushing, pulling, and rotating. In cerebrovascular interventions, interventional neuroradiologists are often faced with tortuous and complex anatomies that can be challenging to navigate and require a high level of skill and expertise [2]. An alternative to manual catheter and guidewires is a robotic approach using robotic magnetic navigation (RMN). In RMN, magnetic instruments composed of a flexible magnetic tip are redirected by the external magnetic field generated by a magnetic navigation system (MNS) [3]. In neurovascular radiology, where the instruments are navigated under radiological guidance, x- ray images of the patient anatomy and the instruments are displayed on a monitor. Under these circumstances, the steering of magnetic catheters and guidewires can be challenging, because they are 3D objects moving in a 3D environment, whereas the operator is provided a 2D image on a 2D display. Companies such as Stereotaxis make use of graphical representations of the magnetic field, the magnetic instrument, and the patient anatomy to help the operator in making the mental transformations [3]. Adding visual cues such as graphical overlays or a separate monitor have the potential to divert the doctor’s gaze away from the x-ray image. This can lead to loss of focus and potentially increase risk. In this work, we propose a new interface that allows the steering of magnetic instruments without the need of additional visual feedback other than the already available 2D fluoroscope image.